Study On Preparation Of Nano-sized Atrontium Titanate Crystalline Powder By Phase Transfer Assisted Hydrothermal Method

Sr Ti O3 is an important fundamental material of ceramic because of its excellent performance. Sr Ti O3 powders are widely used in the sensors, multilayer capacitors, VSR varistor and other electronic components.In this paper we studied respectively hydrothermal method and phase-transfer separation assisted hydrothermal method to synthesize Sr Ti O3 powders, which were characterized and analyzed to explore the optimum parameters of the two methods.In the process of synthesizing powders by hydrothermal method, By using Sr(NO3)2, Ti(OC4H9)4 as raw materials, KOH as the mineralizer, we prepared successfully the Sr Ti O3 powders. Samples were characterized by XRD, SEM. The results show that the hydrothermal method can be used to prepare Sr Ti O3 powders which have good crystalline, the particle size of Sr Ti O3 powders is between 60~110 nm. But the prepared Sr Ti O3 powders appear inevitable phenomenon of the reunion.In the process of synthesizing powders by the phase-transfer separation assisted hydrothermal method, we firstly, using Sr(NO3)2, Ti(OC4H9)4, KOH as raw materials, SPAN80 as surfactant and petroleum ether as solvent, prepared the Sr Ti O3 precursor by the hydrothermal method. Then SPAN80 and petroleum ether would be joined into the above Sr Ti O3 precursor to achieve nano Sr Ti O3 powders. Sr Ti O3 powders were characterized by XRD, SEM, TEM- EDS and Laser Particle Size Analysis. The paper mainly study the content of SPAN80 on the properties of Sr Ti O3 and find out the optimum parameters of this method.The results show that the phase structure of the phase-transfer separation assisted hydrothermal method preparing Sr Ti O3 powders is same to the phase structure of the hydrothermal method preparing Sr Ti O3 powders, with the smaller particle size. The phase-transfer separation assisted hydrothermal method can successfully prepare nano Sr Ti O3 powders. The optimum parameter was that he concentration of mineralizer is 1.8 mol/L, the temperature of reaction is 130 ℃, the time of reaction is 20 h and the adding amount of SPAN80 is 10 %(volume fraction). Under the optimum parameter, the Sr Ti O3 powders have a good homogeneity, pure without impurities and the rule morphology(showing spherical morphology), having no agglomeration or minimal agglomeration. The particle size is about 38 nm and the polar surface of Sr Ti O3 becomes non-polar, having better dispersion.